<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
		<style type="text/css">
			#div1{
				width: 200px;
				height: 200px;
				border: 1px #000000 solid;
			}
		</style>
		<script type="text/javascript">
			function addHeight(){
				var a = document.getElementById("div1");
				var height = document.defaultView.getComputedStyle(a,null).height;
				var newheight = parseInt( height)+10 + "px";
				a.style.height =newheight;
			}
		</script>
	</head>
	<body>
		<div id="div1">
			
		</div>
		<input type="button" value="给div的高度加10" onclick="addHeight()" />
	</body>
</html>
